Communication node with digital plane interface

ABSTRACT

A solution is provided that can be used in a communication node. A case is provided that supports a first circuit board that is connected to a second circuit board via a connection. The first circuit board supports an integrated circuit module and the second circuit board supports a PHY module. A transformer box is mounted on the first circuit board and supports terminals for engagement with a mating connector. A third circuit board can be provided that is parallel to the second circuit board and is mounted on the transformer box so that termination of signals provided to the terminals can take place on a different circuit board than the second circuit board. The third circuit board can also provide power over Ethernet (POE) circuitry.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 62/209,448, filed Aug. 25, 2016, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This disclosure relates to field of network switches, more specifically to an architecture that allows for improved performance and reduced costs.

DESCRIPTION OF RELATED ART

Switches and routers and other communication devices (which shall collectively be referred to as a communication node herein) are commonly used to provide communication between different computing devices. The computing devices, which can take a variety of forms, may be located within a rack in a server or may be located in dispersed locations in the same server room, within the same building or somewhere else entirely. Regardless of the location of the computing devices, the communication node will include a plurality of ports that allow cables to connect the communication node to the various computing devices.

FIG. 1 illustrates a typical communication node 10. The communication node 10 includes a case 14 with a face 15 that has a plurality of ports 18. The ports can be a variety of different configurations, such as, without limitation, QSFP receptacles, SEP receptacles, 8P8C (commonly known as an RJ45, which is the term that will used herein) or other desirable configuration and can be stacked, ganged or in a single port configuration. As can be appreciated, while ports are depicted as being on the face 15, they can also be on other (and even multiple) faces of the case 14 if desired.

The case 14 supports a circuit board 30 (sometimes referred to as a motherboard) that in turn supports integrated circuit (IC) module 35. The IC module 35 can include various processing and memory components as is known in the industry and the desired level of functionality will depend on the purpose and application that the communication mode is intended for. The circuit board 30 also supports a PHY module 45. The PHY module 45 is configured to connect a link layer device (which can be referred to a media access control or MAC) to a physical medium such a copper cables or optical fibers. Thus the PHY module 45 takes digital signals from the IC module 35 and converts those signals into analog signals that can be transmitted over cables and optical fibers. The PHY module 45 also receives analog signals and converts those signals into digital signals that can be provided to the IC module 35. As can be appreciated, the PHY module 45 can includes a number of functional circuits that can be combined as needed to support the particular protocol(s) being supported.

As can be appreciated, the circuit board 30 tends to be relatively large as it needs to support the IC module 35 (which can be a combination of a number of different ASICs), as well as memory and other desired circuitry) and it also supports the PHY module 45 (that needs to communicate with the IC module 35) and needs to have sufficient space to allow the various ASICs positioned on it to be cooled (which may require heat sinks to be mounted on the corresponding ASIC). The circuit board also supports ports 60.

The ports 60 can be provided in a variety of configuration, such as, without limitation, a combination of one or more of the industry standard receptacles mounted on the circuit board 30. Examples of possible standard designs include, but are not limited to, SFP, QSFP, CXP, CFP, OCULINK or any other desirable connector configuration. As can be further appreciated, the ports need not be configured for a particular industry standard.

One issue that exists with the current architecture is that it tends to be costly to implement. The PHY module 45 communicates with the ports 80 using analog signals while the PHY module 45 communicates with the IC module 35 using digital signals (thus the PHY module 45 provides a transition between the digital and analog part of the communication channel). This creates a number of issues. One issue is that the digital side of the communication channel tends to require more layers of circuit board in order to provide the appropriate number of channels of communication between the various circuits that make up the IC module 35. This can result in a circuit board with a larger number of layers, which increases the cost of the entire system. As a result, certain individuals would appreciate further improvements in the configuration of a communication node 10.

SUMMARY

An architecture is disclosed for use in devices that are configured to operate as a communication node. A case is provided that supports a first and second circuit board. The first circuit board is configured to transmit digital signals to support an integrated circuit (IC) module. The second circuit board is configured to support both digital and analog signals. The first circuit board is connected to the second circuit board via one or more connectors. The second circuit board supports a port module that includes a plurality of ports that are provided on a face of the housing. The use of the two circuit boards allows for a digital plane interface between the plurality of ports and the IC module.

A transformer box can be mounted on the second circuit board and can include a first terminal set that is configured to engage a mating connector. A transformer can be used to couple the first terminal set on a line side of the transformer to traces on a chip side of the transformer. A third circuit board can be aligned next to the transformer box in a parallel orientation to the second circuit board and the signal termination can take place on the second circuit board. The third circuit board can configured to provide power over Ethernet (POE) to the first terminal set.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements and in which:

FIG. 1 illustrates a perspective view an embodiment of a prior art communication node.

FIG. 2 illustrates a schematic representation of a prior art communication node.

FIG. 3A illustrates a schematic representation of an embodiment of a communication node.

FIG. 3B illustrates another schematic representation of an embodiment of a communication node.

FIG. 3C illustrates another schematic representation of an embodiment of a communication node.

FIG. 4 illustrates another schematic representation of an embodiment of a communication node.

FIG. 5 illustrates another schematic representation of an embodiment of a communication node.

FIG. 6 illustrates a perspective view of an embodiment of a port module and a plurality of circuit boards.

FIG. 7 illustrates another perspective view of the embodiment depicted in FIG. 6.

FIG. 8 illustrates a perspective exploded view of the embodiment depicted in FIG. 6.

FIG. 9 illustrates a simplified perspective view of the embodiment depicted in FIG. 6.

FIG. 10 illustrates another perspective view of the embodiment depicted in FIG. 9.

FIG. 11 illustrates a simplified perspective view of the embodiment depicted in FIG. 9.

FIG. 12 illustrates an enlarged perspective view of the embodiment depicted in FIG. 11.

FIG. 13 illustrates a partially exploded perspective view of the embodiment depicted in FIG. 12.

FIG. 14 illustrates an exploded perspective view of an embodiment of a transformer box mounted on a circuit board.

FIG. 15 illustrates a simplified perspective view of the embodiment depicted in FIG. 12.

FIG. 16 illustrates a perspective cross-sectional view of the embodiment depicted in FIG. 15, taken along line 16-16.

FIG. 17 illustrates a partially exploded perspective view of the embodiment depicted in FIG. 16.

FIG. 18 illustrates a schematic representation of an embodiment of a transformer.

FIG. 19 illustrates a perspective view of an embodiment of a transformer box.

FIG. 20 illustrates another perspective view of the embodiment depicted in FIG. 19.

FIG. 21 illustrates another perspective view of the embodiment depicted in FIG. 19.

FIG. 22 illustrates a perspective simplified view of an embodiment of a port module and a plurality of circuit boards.

DETAILED DESCRIPTION

The detailed description that follows describes exemplary embodiments and the features disclosed are not intended to be limited to the expressly disclosed combination(s). Therefore, unless otherwise noted, features disclosed herein may be combined together to form additional combinations that were not otherwise shown for purposes of brevity.

FIGS. 3A-5 schematically illustrate embodiments of a communication node 100. It should be noted that the schematic representations depicted in FIGS. 3A-5 are intended to be positioned in a case and thus are expected to be compatible with conventional communication node construction, at least with respect to the external interface that allows the communication node to be mounted in a server rack and communicate with other devices.

Looking at the FIGS., a case 114 (which can be formed of a conductive material) supports a first circuit board 130 that in turn supports an IC module 135. In an embodiment the circuit board 130 is supported by legs 195 that support the circuit board above the case 114. The circuit board 130 will typically have 6 or more layers and can include 24 or more layers if desired. As noted above, the IC module 135 can include a number of separate components, including digital processors, digital signal processor circuits, memory, encryption circuits and the like, that are in communication with each other. Thus, the IC module 135 can be configured in any desirable manner with any desirable set of ASICs that provide the desired functionality and these components are being collectively referred to as the IC module herein.

The case 114 also supports a second circuit board 140 (as depicted the second circuit board 140 is supported by legs 195 but could also be supported by other mechanical structures) The second circuit board 140 supports a PHY module 145 that is configured to receive and send analog signals and send and receive digital signals. The PHY module 145 is in communication with the first circuit board 130 (and thus the IC module 135) via connector 180 and/or connector 181, which can provide a number of channels for communication therebetween. In an embodiment the connector(s) can provide more than 40 channels of communication. Because the signals between the PHY module 145 and the IC module 135 are digital, the PHY module 145 can be spaced apart from the IC module 135 by significant distances (e.g., more than 13 cm) if desired.

The PHY module 145 is also in communication with a port module 160, which can be a plurality of ports in one or more desired configurations. The port module 160 provides an interface that allows the PHY module 145 to communicate with external components.

As the circuit board 140 is separate from the circuit board 130, the number of layers provided on the circuit board 140 can be different than the number of layers on the circuit board 130. In an embodiment the circuit board 140 can have about 6 layers while the circuit board 130 can have 8 or more layers.

One additional advantage of the bifurcated circuit board design depicted is that the circuit board 140 can be made of a higher performing material. As is known, when supporting high data rates it is often necessary to use signaling frequencies that approach 10 or more GHz. A 50 Gbps channel, for example, might require the use of signaling at 25 GHz (if NRZ encoding is used, for example). Typical circuit board materials, such as FR4, are poorly suited to such high frequencies and create significant insertion loss at frequencies about 10 GHz. Other materials exist that are better suited to high frequencies common in analog circuits but tend to be substantially more expensive. Materials such as NELCO-N4000, for example, provide a much lower loss as high frequencies.

Consequentially, the depicted design allows for selective use of materials. For applications where the PRY module is working with higher frequencies it is possible to use an alternative material for circuit board 140 with losses that are 25% or more lower than what FR4 would provide while continuing to use FR4 for digital circuits (as FR4 is often suitable for digital circuits where the issues that are present in an analog circuit are not nearly as problematic). This allows the selective use of materials, based on the application requirements, without using more layers or more expensive materials where they are not needed. And for situations where the circuit board 130 needs a higher number of layers to manage all the channels of communication, the circuit board 140 can be made of some lesser number of layers (typically not more than 6 layers will be needed) and thus oiler a cost savings that extends over the entire surface of the circuit board 140.

As can be appreciated, while two circuit boards are shown, additional circuit boards could be added. In an embodiment, for example, a first circuit board that is intended to work with digital signals could be position in the housing and could be coupled to second circuit board and a third different circuit board, the second and third circuit boards configured to provide analog signals. The second and third circuit boards could be positioned adjacent each other and could also be positioned on two different sides of the first circuit board. Thus, the depicted embodiment provide for substantial architectural flexibility.

FIG. 3B illustrates additional features that can be incorporated into a communication node. Specifically, it includes an IC module 135 supported by a circuit board 130 that communicates with a PRY module 145 on circuit board 140 via signal communication assembly 190. The use of signal communication assembly 190 (which can be connectors and cables) such a system is expected to significantly reduce losses between the circuit board 130 and the circuit board 140 as the signal communication assembly 190 will tend to have lower loss than the use of circuit board materials. This will allow the circuit board 130 to provide the desired functionality without the need to worry about transmitting signals across a substantial distance.

Additional features include a power source 134 that can provide power to the circuit board 140 with power transmission assembly 191 (that can also include cables and connectors). As in FIG. 3A, a port module 160 is provided to allow the communication node to communicate with external devices. A power regulator can be included with the PHY module 145 so as to ensure the power provided by the power source 134 is suitably controlled (which will, in certain circumstances, allow the port module to operate more effectively) An additional communication assembly 192 can be used to help control the operation of the PHY module 140 by providing various communication, control and timing signals, as desired, to ensure the PHY module 140 is operating in an intended manner.

FIG. 3C illustrates another embodiment that is similar to the embodiment depicted in FIG. 3B but includes separate circuit boards 140 a-140 d that each support a port module 145 a-145 d, respectively. Each circuit board 140 a-140 d also supports a respective PHY module 145 a-145 d and a respective port module 160 a-160 d. The power transmission assembly 191 and signal communication assembly 190 are also included but can be configured so that a separate path is provided to each of the circuit boards 140 a-140 d. Control communication assemblies 192 a-192 d, which can extend between two circuit boards 140 a-140 d or between the circuit board 130 and one of the circuit boards 140 a-140 d or some combination thereof, allow for the provision of communication, control and timing signals to the MY modules 145 a-145 d as desired.

FIG. 4 illustrates a schematic representation of the features depicted in FIG. 3A and illustrates a potential physical orientation. As can be appreciated, supports 195 can be used to support the circuit boards 130, 140 in a case 114 so that port module 160 is positioned on a face 115 of the case 114. As noted above, one or more connectors 180 (which can be any desired type of connector system such as a cable assembly or board to board connector) can be used to provide signal paths between the circuit board 130, 140.

FIG. 5 illustrates a schematic representation of an embodiment with a configuration that includes features of the port module 160 and PHY module 145 combined but in a particular physical configuration that has been determined to be beneficial for certain applications. As depicted, a first circuit board 202 is configured to support a contact and magnetics assembly 201 on a first side (and as depicted, optionally on a second side) and the first circuit board also supports a signal modulation circuit 206 (the signal modulation circuit is typically part of the PHY module 145). A communication connection 205 allows the signal modulation circuit 206 to communicate with an ASIC in a digital fashion while a voltage connection 208 is provided to support the signal modulation circuit 206.

The contact and magnetic assembly 201 includes a line interface 220 (which is typically part of a port module and can be an RJ45 connector or some other desirable interface) that is connected to magnetics 221. The magnetics 221 functions in a conventional manner and allows for communication of signals between the line interface 220 and a device interface 222 while providing some electrical isolation. As depicted, the line interface 220 terminates to a second circuit board 203 via a termination circuit 204, which can be any desired termination circuit. The device interface 222 is connected to the first circuit board 202 and thus to the signal modulation circuit 206. As can be appreciated, therefore, the line interface 220 can be electrically isolated from the first circuit board 202 even though the signal modulation circuit 206 is configured to provide signals to the line interface 220 via the magnetics 222.

One benefit of the depicted configuration is that the second circuit board 203 (which would be a third circuit board in a system where a separate circuit board was used for a IC module) can include power injection into the termination via a power connection 207 and in an embodiment the power can be inserted into the twisted pair via a termination circuit such as termination circuit 204 while ensuring there is good electrical isolation between the first circuit board 202 and the second circuit board 203 (as can be appreciated from the depicted embodiment, there can be two second circuit boards 203). This can potentially reduce the need for isolation capacitors and can, even if the isolation capacitors are used, allow for improved performance as the first circuit board 202 can be optimized for signal performance and/or made smaller without the need to compensate for electrical isolation.

The second circuit board 203 also includes a communication connection 205 and a regulation circuit 209. It should be noted that each circuit can include a connection to other components and thus the depicted configuration allows for wires/cables to be connected to the illustrated circuits.

As can be appreciated, the second circuit board 203 can be positioned on two sides of the first circuit board. Power for the provision of Power-over-Ethernet (POE) can be provided on the second circuit boards 203 and thus POE power can be kept separate from the first circuit board 202. Numerous benefits can be provided by the depicted configuration

FIGS. 6-22 illustrate an exemplary configuration of the embodiment that is schematically represented in FIG. 5. It should be noted that the depicted embodiment does not show all the circuitry for purposes of brevity as the particular circuitry used will depend on the chips mounted on circuit board as well as the desired functionality and capabilities of the final assembly and the chip(s) being used. It should also be noted that circuitry is intended to be inclusive of any desirable configuration and could be, without limitation, an FPGA chip, a module, a transceiver or any desirable combination of components and integrated circuits.

The depicted front module assembly 325 includes a port module 360 that includes a housing 361 with a cage 362 that at least partially extends around a perimeter of the housing 361. The port module 360 defines upper ports 360 a and lower ports 360 b. Typical front module assemblies will include a plurality of ports in a stacked and ganged configuration (as depicted) and it should be noted that a port module can readily include more or less than the depicted 6 ports and in alternative embodiments the configuration may not include stacked ports. As can be appreciated, one benefit of the stacked configuration is the ability to reduce costs compared to a pure ganged configuration, as will be discussed further below.

The depicted front module assembly 325 includes a first circuit board 312 and two second circuit board 313. The first circuit board 312 can include circuitry 316 that receives and transmits signals and thus the circuitry 316 will typically include a PHY module as well as other desirable chips and components (such as a media independent interface chip or microcontroller) used to filter and modify received and sent signals, as well as to communicate with the digital part of the system. In the depicted configuration the first circuit board does not include Power over Ethernet (POE) elements and instead the power insertion circuitry (which can be conventional POE circuitry) and any desired termination circuitry (such as the termination known as the Bob-Smith termination) can be included on the second circuit boards 313. As can be appreciated, such a configuration allows the power insertion componentry and higher voltage touching components to be provided on the second circuit board 313, thus allowing for a simpler layout on the first circuit board 312. A cable connection (not shown), such as power communication assembly 191 depicted in FIG. 3C, can be included as desired to provide power to the second circuit board 313. While not shown for purposes of brevity, the first circuit board 312 will also include a signal communication assembly 190 to allow the first circuit board 312 to communicate with a processor provided on another circuit board.

As can be appreciated, the first circuit board 312 supports a transformer box 340. In a ganged configuration a plurality of transformer boxes 340 can be positioned side-by-side on the first circuit board 312. In a ganged configuration, transformer boxes 340 can be positioned on two sides of the first circuit board (such as is depicted in FIG. 9). Each transformer box 340 includes transformer housing 340 a and a terminal frame 343 that supports a first terminal set 341 a, 341 b and the transformer boxes, if desired, can be configured the same on both sides of the first circuit board 312. As depicted, the first terminal sets 341 a, 341 b provide a row of terminals 342 and the terminal frame 343 is integral with the transformer housing 340 a. In an embodiment the row of terminals 342 is positioned in a comb 364 provided by the housing 361 but such a construction is not required. The transformer box 340 can optionally support one or more light pipes 359 and a corresponding light emitting diode (LED) can be positioned on the circuit board 312 so that the LED is covered by the transformer box 340.

The transformer box 340 supports a plurality of transformers 346 that are used to pass the signals received from the first terminal sets 341 a, 341 b (from a line side) to second terminal sets 344 (e.g., to a chip side) that can be connected to a chip (such as a chip in a PHY module) on the circuit board 312. The first terminal set 341 a includes tails 343 a that can be connected to wires. As can be appreciated, the transformer box 340 includes an interior 345 and is depicted as providing a transformer 346 (which includes a ferrite core 347 a and windings 347 b) that magnetically couples the signal wires connected to the tails 343 a of first terminal set 341 a, 341 b to signal wires that are connected to tails 344 a of the second terminal set 344. The second terminal set 344 also includes solder tails 344 b that can be soldered to the circuit board 312. The transformer box 340 also includes board retention members 348 a, 348 b that can be used to secure the transformer box 340 to the respective circuit boards 312, 313.

If desired, the transformer box 340 could be increased in size and also used to support one or more filtering components. The transformer box 340 is also depicted as including termination pins 349, which are configured to engage vias 355 in the second circuit board 313. The termination pins 349 can be connected to a centertap of each pair of wires and can provide, in combination on the second circuit board 313 a Bob-Smith termination or some other desirable termination (as noted above). Thus the termination pins 349 can be connected to the centertap CT in FIG. 18 (which naturally allows for power insertion into the transformer by applying a voltage to the centertap CT). Such a voltage, as is known, is electrically separated from the centertap CT′ (which is on the chip side) and thus the chip side (S′+, S′−, CT′) do not require high voltage separation (such as could be provided by a 2 kV capacitor). As the use of transformers for signal coupling and power insertion compatible with POE standards is well known, no further discussion will be provided herein. As can be appreciated, the depicted configuration allows for the termination of the line side signals to be done on the second circuit board 313 while the signals are pass through the transformer so as to be provided/passed to traces on the first circuit board (for eventual connection to a PHY module). Naturally, if the second board is not provided then the termination could also occur on the first circuit board 312 but such a configuration may require more space on the first circuit board 312.

The depicted transformer box 340 includes a front aperture 352 and a rear aperture 353. It has been determined that the inclusion of the front and rear apertures 352, 353 are beneficial in forming the transformer box 340 as it allows the first set of terminals 341 a and the second sets of terminals 344 to be insert-molded into the transformer housing 340 a (the apertures provides a way to hold the terminals in the desired position). In an embodiment the first and second terminal sets each have their respective tails bent/extending away from the aperture aligned with the corresponding set of tails. In the event that it is desired, the transformer box can also include a notch 354 to allow for a channel of air communication through the transformer housing 340 a at a location aligned with the tails 344 a. This could be desirable, for example, if the tails 344 a were also soldered to the circuit board 312. It should be noted that once the internal components of the transformer box 340 are electrically connected together the internal components can be epoxied or potted in place to help secure and protect the wires/ferrite core used to provide the desired functionality.

As can be appreciated from FIG. 22, the first circuit board 312 and the second circuit board 313 are positioned on opposite side of a transformer 346 such that the first circuit board can define a first plane 371, the second circuit board 313 can define a second plane 372 and the transformer 346 can define a third plane 373, the third plane 373 being aligned with a center of the transformer 346, wherein each of the planes 371-373 are parallel to each other and the third plane 373 is parallel to the first plane 371 and between the first plane 371 and second plane 372. The transformer 346 includes a line side electrically connected to first terminal set 341 and includes a chip side electrically connected to terminal set 344. As can be appreciated, power can be inserted in the second plane 372 and thus the third plane 373 electrically connects the second plane 372 with the first plane 371 so that power can be supplied to the first terminal set 341 a. The terminal set 344 is positioned on the first plane 371 and is electrically isolated from the first terminal set 341 a. Thus, on the line side, power can be provided in the second plane 372, pass through the third plane 373 to the first plane 371 while being kept isolated from the chip side on the first plane 371.

The disclosure provided herein describes features in terms of preferred and exemplary embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. 

We claim:
 1. A communication node, comprising: a case having a first face; a first circuit board supported by the case, the first circuit board supporting an integrated circuit (IC) module; a second circuit board supported by the case, the second circuit board supporting a PHY module; a port module supported by the second circuit board and in communication with the PHY module via the second circuit board, the port module providing a plurality of ports in the first face; and a connector electrically connecting the first circuit board to the second circuit board, wherein the PHY module is in communication with the IC module via the second circuit board, the connector and the first circuit board.
 2. The communication node of claim 1, wherein the first circuit board has a first number of layers and the second circuit board has a second number of layers, the first number being greater than the second number.
 3. The communication node of claim 2, wherein the first face is at least 13 cm from the IC module.
 1. A communication node, comprising: a case with a front face; a first circuit board positioned in the case; an integrated circuit (IC) module supported by the first circuit board; a second circuit board positioned in the case, the second circuit board have a first side and a second side; a PHY module supported by the second circuit board; a connector configured to provide communication between the IC module and the PHY module; a first transformer box and mounted on the first side; and a second transformer box mounted in the second side, wherein the first and second transformer boxes each have a housing with an interior and the housings each supports a first terminal set and a second terminal set, wherein each first terminal set is configured to engage a mating connector and the second terminal set is configured to be connected to traces on the second circuit board, wherein the first and second terminals sets in each transformer box are coupled via a transformer provided in the transformer box and both the first and second terminals sets extend into the interior of the respective transformer box.
 5. The communication node of claim 4, wherein a third circuit board is mounted on the first transformer box, the third circuit board including a termination for the first transformer box.
 6. The communication node of claim 5, wherein the first terminal set is aligned with a first plane that is parallel to the first circuit board and the termination is provided on a second plane that is parallel to the first plane, the first and second plane spaced apart, wherein a third plane parallel to the first plane can be defined as extending through a center of the transformer and the third plane is positioned between the first and second plane.
 7. The communication node of claim 5, wherein the third circuit board includes power over Ethernet (POE) circuitry and is configured to provide power to the first terminal set.
 8. The communication node of claim 4, wherein the first and second terminal sets are insert molded into the housing.
 9. The communication node of claim 8, wherein the housing includes a first aperture aligned with tails of the first terminal set and further includes a second aperture aligned with tails of the second terminal set.
 10. The communication node of claim 9, wherein the tails of the first terminal set are bent so as to extend away from the first aperture.
 11. The communication node of claim 4, wherein the first circuit board has a first number of layers and the second circuit board has a second number of layers, the first number being greater than the second number. 